Preoperative hormone therapy trials for breast cancer

Preoperative hormone therapy for breast cancer has the potential to downsta ge a primary tumour hence increasing operability as well as making breast c onservation feasible. Whether it will achieve any clinically significant su rvival benefit remains to be elucidated. Preoperative hormone therapy, in c ontrast to neoadjuvant chemotherapy, produces less severe side effects and can be continued throughout the perioperative period. Presurgical studies h ave demonstrated anti-tumour effects of hormone therapy, e.g. down-regulati on of ER. Current clinical trials have shown that, in patients with ER posi tive tumours, a response approaching 70% is reached in approximately three months using the traditional hormonal agent tamoxifen. The tumour seldom pr ogresses during this period. New agents (such as third generation aromatase inhibitors and pure anti-oestrogens) may produce more profound and rapid r esponses. Future trials are required to identify factors other than ER to p recisely predict response so that appropriate patients can be selected. The best agents, the ideal methods of monitoring response and the optimum dura tion of therapy also need to be identified. Clinical trials also need to te st if pre- and perioperative hormone therapy is superior to conventional ad juvant hormone therapy in patients with early breast cancer. (C) 2001 Harco urt Publishers Ltd.